MONDAY, April 17 (HealthDay News) -- Glucocorticoids released from the adrenal glands during emotional experiences help strengthen new memories in rats and may have important implications for human drug development, according to a report published online April 12 in the Proceedings of the National Academy of Sciences Early Edition.
Benno Roozendaal, Ph.D., from the University of California in Irvine, and colleagues investigated whether noradrenergic activation of the basolateral complex of the amygdala (BLA) -- a region responsible for processing emotions -- triggered by an emotional experience is critical for glucocorticoid effects on memory consolidation.
Rats given corticosterone immediately after exposure to a new object did better on memory tests than untreated rats 24 hours later, but rats that were already familiar with the object showed no improvement with corticosterone treatment. Propranolol, a beta-blocker that shuts down norepinephrine signaling in the amygdala, prevented the effect of corticosterone on memory enhancement.
"These findings strongly suggest that synergistic actions of glucocorticoids and emotional arousal-induced noradrenergic activation of the BLA constitute a neural mechanism by which glucocorticoids may selectively enhance memory consolidation for emotionally arousing experiences," the authors write. "Potential cognitive-enhancing drugs may modulate memory consolidation only under conditions that induce sufficient noradrenergic activation of the BLA."
Abstract
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